Internal combustion engine



Patented Dec. 18, 1934 UNITED srirrlas nrrEaNAL coMUs'rIoN ENGINE Herbert E. Buckle, Elkhart, 1nd., assigner of one-half to John A. Dienner, Evanston, Ill.

Application June zz', i932, serial No. 613,622 4 claims. (ci. 12s-47) The present invention relates to internal combustion engines and is more particularly concerned with a novel intake valve and the method of operation thereof. While thepresent inven- 5 tion is of general application it ismore particularly applicable to two cycle engines, especially such as are used on outboard motors, or other. marine engines.

In a two cycle engine the exploded gases are `discharged from the working cylinder as the piston approaches the end of its working stroke, and a fresh mixture isl admitted into the explosion chamber even while the exhaustion of the previously exploded gases is taking place.A kOnly a small portion of the interval required for one stroke of thepiston is allowed for exhausting of the burned and, preferably, also a rather large intake opening.v This has generally precluded the yuse of a simplified valve arrangement for controlling the exhaust and the intake. It has, heretofore, been proposed to use a rather simple ring valve carried by the piston and having frictional engagement with the cylinder wall for controlling theadmission offuel into the explosion chamber. In so far as I am aware, such an arrangement has al'- ways precluded lthe use of a large exhaust port unless a complicated exhaust valve arrangement was also used.

Now, according to my present invention, the exhaust port comprises one'or more openings extending partly, or entirely, around the periphery n of the cylinder wall, such port being maintained closed during the compression stroke and during the explosion stroke by the skirt vof the piston. As the piston approaches the limit of its-explosion strokeit uncovers the exhaust port and per- 40 mits the escape ofthe ignited gases. The intake port. comprises a passageway extending `.through the working face of the piston and opening into the skirt portion thereof, which skirt portion is in direct communication with the-crank case of the engine, as in the usual-practice. The passage-k way is controlled by a valve which. comprises a piston ring and which,at all times,l maintains the passageway Vclosed off fromtheperiphery of the piston. By this arrangement it is, possible to extend the exhaust port around the entire periphery of the kcylinder wall without incurring the danger of providing a direct passageway between the exhaust port and the crank case wherein the fuel mixture is compressed'previous to being introduced into the explosionchanber. -The valve is Therefore, for the best results, `it isV subject totwo operating forces, namely, ring friction and pneumatic pressure difference. 'I'he pneumatic pressure difference maintains the valve closed, against the ring friction, duringthe explosion stroke, and permits the opening of the valve by ring pressure only after asubstantial exhaustion of the ignited gases. During the compression stroke the pneumatic pressure assists the ring friction in maintaining the valve closed.

In its simplest embodiment my present invention comprises a check valve carried by the'piston for permitting the flow 'of fuel from the crank case -to the piston when the pressure within the crank case exceedsk that within the explosion chamber, and preventing such flow when the pressure within the explosion chamber exceeds the pressure within the crank case. In its more elaborate form the vcheck valve is brought out to the peripheral wall of the piston whereby it engages the cylinder Wall and is actuated, in one direction,

'by the friction between it and the cylinder wall.

'I'he checkvalve and the exhaust port extend at least along the major part of the circumference of the piston and cylinder wall, respectively, and therefore the check valve is arranged to prevent communication between the fuel intake passageway and the exhaust port.

. The attainment of the above and further objects of the present invention will be apparent from the following specification taken in conjunction with the accompanying drawing forming a part thereof.V

In the drawing: y

Figure 1 is a transverse section through an engine embodying the principles of my invention;

Figure 2 is an enlarged View showing the valve arrangement of the engine shown in Figure 1;

Figure 3 is an end view of the piston of the engine shown in Figure 1; and

`Figure 4 is an interior view of the piston. The engine shown and described in the vpresent applicationis of the opposed cylinder type and ghastwo cylinders 1 and 2 offset with respect to one another and connected to a common crank case 3. The cylinders have cylinder walls 4-4, preferably cast integral with the Walls 5-5 of a water jacket surrounding the working cylinders. The piston 7-8 of the two cylinders are arranged to beboth moved inwardly at the same time and to be both moved outwardly at the same time and to actuate the crank shaft comprising crank discs 10, all in a manner well known in the'art.

The .cylinder blocks are preferably cast each as one piece and are provided with flanges 11 whereby they may be suitably secured to the crank case 3. The crank case provides a separate chamber for each pair of cylinders. The cylinder blocks are provided with exhaust ports which extend completely around the periphery of the cylinder. Lands or webs 16, comprising an integral part of the cast cylinder block, define a pluralityof exhaust passages along the periphery of the cylinder wall 4, said passages being indicated at 17. Th ese passages lafford communication between the. interior of the cylinder and a manifold 18 that extends around the periphery of the ycylinder block. The exhaust openings 1'7'are overrun by the piston 7 and are opened only at the end of the explosion stroke of the piston.

The pistons '1 and 8 are of identical 'construction and a description of one will suiiice for the other also. The piston 8 includes a skirt portion 20 adapted to slide in the cylinder wall 4, and has a head member 21 secured thereto. A T-shaped groove, extending around the entire periphery of the piston, is formed between the skirt portion 20 and the head portion 21 of the piston. A T-shaped valve 25.rides in this opening. The valve 25 may comprise a single closed ring of a T section. If desired two or more T shaped portions of a circle may be used to extend around the 360 of the piston. It is desirable that the T-shaped opening should extend completely around the circumference of the piston, as above set forth, in order to provide a maximum intake port opening. However, if desired, the T-shaped slot may extend around the periphery of `the piston for a distance less than 360, in which case the T-shaped valve member 25 would be correspondingly reduced. The flange 26 of the T- shaped valve 25 extends between the cylinder wall 4 and the piston and closes the T-shaped opening in the piston to define a valve chamber 28 that is closed from communication with the cylinder wall and therefore closed from communication with the exhaust port. Sealing rings 29 and 30 seal the chamber 28 from the cylinder wall. A ring 31, which may comprise a piston ring, or merely a friction member, surrounds the T-shaped valve ring 25 and affords a frictional engagement with the cylinder wall 4. The ring 31 is preferably a split ring and therefore also serves to maintain the parts oi' the valve ring 25 together during assembly of the unit and before the piston has been inserted into the vcylinder block. A plurality of openings 35 are formed in the ends of the skirt portion 20 of the piston and afford communication between the crank case and-the valve chamber 28. These holes 35 may be cored in the piston at the time it is cast. A plurality of openings 36 are formed in the piston head 21 and aiford communication between the valve chamber 28 and the explosion chamber formed between the end of the cylinder and the piston. The stem 38 of the T-shaped ring valve constitutes the valve portion thereof for closing and opening communication between the passageways 35 and the valve chamber 28, and thereby controls communication between the crank case and the explosion chamber.

A fuel-air mixture is admitted into the `crank case under the control of a rotary valve adapted to close off a gas inlet 39 that is connected to the carbureter, or to the intake manifold'which leads to the carbureter. The rotary valve 40 is driven by a gear 41 which in turn' is driven by a gear 42 on the crank shaft. The gear41 makes one revolution for each two revolutions of the crank shaft. Since the valve 40 opens the fuelair passageway twice per revolution of the gear 41 it is apparent that this passageway will be opened once for each complete revolution of the crank shaft.

An explanation will now be given of the mode of operation of the engine thus far described. 'Ihe pistons are shown in the positions occupied at the commencement of the explosion stroke. At this time the fuel-air mixture has been compressed within the explosion chamber and, upon ignition thereof in the usual manner, the pistons are forced back within the cylinder. The pressure within the explosion chamber is communicated to the valve chamber 28 through the pas- .sageways 36 and maintains the stem 38 of the T- shaped valve over the passageways 35 to close oi those passageways. As the piston continues to move back under the expansion of the exploded gases the pressure of the exploded gases acting upon the stem 38 of the valve 25 serves to' maintain the valve closed against the tendency of the valve to open due to the frictional engagement thereof with the cylinder wall 4. The valve 25 remains closed. At this time the valve 40 is closed and therefore the fuel-air mixture within the l crank case 3 is being compressed. As the piston approaches its iinal position at the end of the explosionstroke it uncovers the exhaust port of the cylinder and permits an escape of the ignited gases within the explosion chamber, Thereafter, as the piston continues to move a slight amount in the same direction, the valve 25 is moved to the position shown in Figure 2 by the friction between the valve and the cylinder wall and by the preponderance of pressure within the crank case over the pressure within the explosion chamber. The fuel-air mixture now ilows from the crank case, through the passages 35, into the valve chamber 28 and thence by way of the passages 36, into the explosion chamber. It iste be noted that the passages 36 are directed towards the center of the piston head. Fresh incoming gases enter the cylinder in advance of the exhaust port and contact, directly with the spark plug, and from there, due to the conical cylinder head,

they spread out on the return path in pursuit of compression stroke and the greater the com-v pression the greater will be the force tending to hold the valve closed. At this time the rotary valve 40 is open and permits the ilow of a fuel-air mixture into the crank case. The rotary valve 40 closes as the piston reaches its limit of travel outwardly of the cylinder.

From the description thus far given it is apparent that I have located the intake port in the piston in such la manner as to by-passthe exhaust port and to permit the placement of the exhaust port around the entire'periphery of the cylinder. *It is further apparentthat the T- shaped valve comprises a check valve that effect tively prevents the opening of the intake port when the pressure within the explosion chamber is in. excess of the pressure within the crank case, that is, when the pressures are such that a reverse now of gases would take place. Also, while I' have shown the valve as of a generally T- shaped cross section this type of section may be departed from without departing from the spirit and scope of the present invention.

In compliance with the requirements of the patent statutes I have herein shown and described a preferred embodiment of my invention. It is, however, to be understood that the invention is not limited to the precise construction herein set forth, the same being merely illustrative of the principles of my invention. What I consider new and desire to secure by Letters Patent is:

l. An internal combustion engine having a cylinder and a piston therein defining therewith an explosion chamber, said cylinder having a discharge port opening in the cylindrical wall thereof, said piston having a skirt portion that slides over the port and maintains it closed during the compression stroke and during the major portion of the explosion stroke, said piston clearing the port as the piston approaches the end of its working stroke thereby permitting the discharge of the products of combustion, said piston having a slot in its outer periphery, a passageway extending to the slot from the inside of the skirt of the piston, another passageway separate from the first passageway and extending from the slot through the piston to the explosion chamber, and

a check valve in said slot controlling the closing and opening of communication between said passageways.

2. An internal combustion engine having a cylinder anda piston therein defining therewith an explosion chamber, said cylinder having a discharge port opening in the cylindrical wall thereof, said piston having a skirt portion that slides over the port and maintains it closed during the compression stroke and during the major portion of the explosion stroke, said piston clearing the port as the-piston approaches the end of its working stroke thereby permitting the discharge of the products of combustion, said piston having slot in its outer periphery, a passageway extending to the slot from the inside of the skirt of the piston, another passageway separate from the first passageway and extending from the slot through the piston to the explosion chamber, and a check valve in said slot controlling the closing and opening of communication between said passageways, said check valve having frictional engagement with the cylinder wall and closing od communication between the discharge port and the first mentioned passageway.

3. An internal combustion engine having a cylinder and a piston therein defining therewith an explosion chamber, said cylinder having a discharge port opening in the cylindrical wall thereof, said piston having a skirt portion that slides over the port and maintains it closed during the compression stroke and during the major portion of the explosion stroke, said piston clearing the port as the piston approaches the end of its working stroke thereby permitting the discharge of the products of combustion, said piston having slot in its outer periphery, a'passageway extending to the slot from the inside of the skirt of the piston, another passageway separate 'from the first passageway and extending from the slot through the piston to thek explosion chamber, and a check valve in said slot controlling the closing and opening of communication between said passageways, said check valve comprising a T-shaped ring thestem of which comprises the valve portion and the flange of which has frictional engagement with the cylinder wall. f

4. A two-cycle explosive engine having a crank shaft compression chamber, a cylinder, a piston within the cylinder, an intake port through the piston for permitting gas ow from the crank case to the explosion chamber of the cylinder, and means for controlling the gas ow into the explosion chamber, said last means comprising a T shaped circumferential slot in the cylindrical portion of the piston, said port extending through said slot, and a T shaped ring valve in said slot, the stem of the T valve comprising a check valve controlling said port, and the flange of the T valve having frictional engagement with the wall of the cylinder for opening and closing the valve during movement of the piston.

` HERBERT E. BUCKLEN. 

